Carburetor



J. S. CULP CARBURETOR June 19, 1934.

Filed May 19', 1930 2 'SheetsSheet l J5 y 5. Cu BY W ATTORNEYS J. s, CULP I CARBURETOR June 19, 1934.

2 Sheets-Sheet 2 Filed. May 19 1930 ATTORNEYS Patented June 19, 1934 UNITED "STATES PATENT; "OFFICE tion of Michigan Application May 19, 1930, Serial No. 453,705 17 Claims. (01. 26134) The invention relates to carburetors and consists in various novel features of construction as hereinafter set forth.

In the drawings:

Figure 1 is a vertical central section through my improved. carburetor showing the parts in idling position;

Figure 2 is a side elevation partly in section;

Figures 3 and 4 are views similar to Figure 1 showing parts in different positions of adjustment;

Figure 5 is an elevation viewed at right angles to Figure 2, and

Figure 6 is a section on line 6-6 of Figure 2. As shown in Figure 1,'A is a casing section attached to the engine inlet manifold and containing a butterfly throttle valve B and a Venturi passage C on-the atmospheric side of the throttle. D is abell shaped casing section surrounding the casing A and E is a tubular casing depending centrally within the casing D and extending into the casing A to a point slightly beyond the restricted throat of the venturi. The upperportion E of the casing E forms a fuel storage chamher and the barrel of a pump. Fitting within this barrel is a cup shaped piston F which is arranged adjacent to a head G loosely flttingthe barrel. The head G has a tubular stem H in the upper portion of which is arranged the stem I ofa needle valve J. In the lower portion of the stem H which passes through a clearance aperture in the piston F is slidably arranged a tube K, the upper end of which cooperates with a needle valve to restrict the areaof the passage. Surrounding both the 'stem H and the tube K is a sleeve L which slidably fits within the casing E and at its lower end is provided with obliquely directed spray apertures L and a central downwardly directed aperture L The. sleeve L is 40 mechanically connected to the throttle through the medium of a tubular link M having spherical ends M, M whichrespectively engage sockets in the lower end of the sleeve L and upon the throttle B at one side of its-axis. The shank I of the needle valve is attached to a supporting member N which is within a hollow cap 0 having a threaded engagement with the upper end of the casing D and a spring P is interposed between the member N and the head G to resiliently pressthe former upward and the latter downwardly. A

fuel supply line Q is attached to the cap 0.

With the parts as thus'far described, it will be understood that the liquid fuel from any suitable I source such as a gravity feed line or a pump line is free to enter through the conduit Q into the space within the hollow cap 0 and past the loose fitting head G to the cup shaped piston F. This piston is normally slightly separated from the head G resting upon .the upper end of the sleeve L .by the resting of the lower end of the tubular stem H on the bottom ,of the recess in the member L and in this position there is an open passage for thefuel between the head G and the piston and through the clearance between said piston and stem H into a clearance space R between said sleeve and the tubular stem H. This tubular stem Hhas a series of apertures S therein permitting the fuel to passfrom the space B. into thishollow stem H and thence past the needle valve into the tube K. From the latter the fuel can pass downward whenever there is any pressure which is in excess of atmospheric pressure, but when the engine is running atmospheric pressure will prevent discharge of fuel through the obliquely arranged jet openings L- When the parts are in the positionshownin Figure 1, that is, where the throttle is substantially closed or in idling position, thetubular connecting rod M will convey fuel from the tube K downward to the throttle and through a registering portT in the latter into the .engine intake. Thus in starting the suction within the intake due to the cranking will draw fuel through the tubular rod M and port Tinto said intake. The liquid fuel may also be commingled with air which is drawn in through the oblique jet apertures L thereby forming an emulsion wh ch in theintake i is commmingled with more air to form .a combustible mixture. As soon, however, as he throttle is turned from itsidling to amore openposition as illustrated in-Figure 3, the rocking of the ball M in its socket will cut off communication between the tubular rod M and port T so that all of the fuel will be-discharged'through the inclined ports L. This movement of the throttle will also draw the sleeve downward which by withdrawing its support from the cup-shaped piston F will permit the spring P to force the head G downward carrying with it the piston and placing a positive pressure on the liquid fuel with-' in the chamber E. Thus the fuel -will-- be discharged under a head developed-bythe tension of the spring P and through an aperture controlled by the needle valve J, said aperture being enlarged as the throttle is opened. During this downward movement of the head G and piston F the head will be pressed against the piston so that an annular bearing G. on the head will seal against the piston and prevent any leakage of the fuel upward. Thus the cup, head and sleeve together function as a check valve, permitting the fuel to pass downward by the piston when the throttle is in idling position by preventing any return movement of the fluid past the piston when the latter is drawn downward. The ball M also functions as a valve which opens communication from the fuel line to the manifold when the throttle is in idling position and closes this communication when the throttle is partly open. y

In operation, the hood D functions as a flame arrester as it causes any backfire flame to reverse its direction and to discharge downward. The hood also has the beneficial effect of a dust remover by causing an initial upward movement of a current of air before it canenter the intake.

As the open area of the hood is considerably in excess of the open area of the casing A the velocity of the upward current of air will be correspondingly slower than that of the descending air currentwhich also will tend to separate out the dust. Normally the fuel is held from discharge by atmospheric pressure but as soon as the engine is started fuel is discharged either through the throttle when the latter is in idling position or through the jet apertures L when the throttle is partly opened. The amount of discharge is regulated by the needle valve J and to permit of adjustment in the setting of this needle valve the casing D which carries the stem I of the valve is adjustable with respect to the casing A. This is preferably accomplished by a screw bolt U which passes through a bearing in the easing D and engages a threaded socket in the member A. A spring V in a recess in the member D and bearing at one end against said member and on the other hand against the member A serves to separate these members whenever the screw U is adjusted to permit such separation. The casing V is held from rotation about the bolt U by a lug W on the casing A which engages a groove guide on the casing D. Thus the turning of the screw U so as to raise the casing D would enlarge the area of the opening past the needle valve while an adjustment of said screw in the opposite direction will restrict such area.

For adjusting idling position of the throttle the throttle stem or rock shaft 13 has mounted thereon an arm B provided with anadjusting screw 13 for engaging a stop Z on the casing A. Thus by adjusting this screw the degree of closing of the throttle for idling position will be regulated.

It will be noted that while the connection between the throttle and' the piston is non-positive, the connection between the piston andtube K which co-operates with the needle valve is positive. Thus while the throttle may be quickly opened, the restriction to the flow of fuel by the needle valve is not removed until there is'positive displacement of the piston by the spring P and the greater the displacement of the piston the larger the opening for the flow of fuel. -This insures'development of sufficient pressure on the liquid fuel to produce a proper spray.

While I have described the nozzle as arranged to discharge downwardly, it is obvious that the operation of the carburetor is not dependent upon this for it would still be operative if reversed in position or arranged at any different angle.

What I claim as my invention is:

1. In a carburetor, the combination with ya downwardly directed mixture inlet having a manually controlled throttle therein, of a noz zle extending downwardly into said inlet, a movable section at the lower end of said nozzle, a needle valvecooperating with said movable section to control the discharge of fuel, and a connecting rod between the throttle and said movable section whereby the latter is opened by the former.

2. In a carburetor, the combination with a downwardly directed throttle controlled mixture inlet, of a vertically adjustable fuel nozzle extending downward into said inlet, fuel metering means controlled by the movement of said nozzle, a hollow connecting rod between the throttle and said nozzle to actuate the latter from the former and also constituting a fuel passage from said nozzle to a port through said throttle in the idling position of the latter, said port being closed by the angular movement of said rod when the throttle is open.

3. In a carburetor, the combination with a downwardly directed mixture inlet, of a butterfly throttle valve controlling said inlet, a fuel nozzle extending downward into said inlet-,a hollow connecting rod between said throttle and fuel nozzle for vertically adjusting the latterby the movement of the former, said rod forming a fuel passage from said nozzle which in the closed position of the throttle registers with a port therethrough, said rod and throttle also constituting avalve for closing said port by theirrelative angular movement during the open,- ing of the throttle.

4. In a carburetor, the combination with a downwardly directed mixture inlet, of a throttle valve in said inlet, a vertically adjustable fuel nozzle extending downward into said inlet and provided with a central discharge. port and one or more laterally directed discharge ports, a hollow con'necting'rod forming a mechanical. connection between said throttle and said nozzle for actuating the latter bythe former and also constituting a fuel passage from said central port to a port through said throttle in the idling position of the latter, said port through the throttle being closed by the relative angular movement of said rod when said throttle is open whereby fuel is :discharged /from said nozzle through the throttle in idling position and is directed laterally into said mixture inlet in the open position of the throttle.

5. In a carburetor, the combination with a downwardly directed mixture inlet, of a throttle valve in said inlet, a vertically movable nozzle extending into said inlet above said throttle, a connection: between said throttle and nozzle foractuating the latter from the former and means automatically operating a plunger adapted to move downward upon the lowering of said throttle so as to constitute a stop preventing movement of said plunger, said hollow rod constituting a fuel passage from said nozzle to a port through said throttlein said idling position and cutting off communication between said port and said nozzle when the throttle is open whereby the opening of the throttle will permit said plunger to eject fuel from said nozzle.

7. A carburetor comprising a downwardly directed'mixture inlet, a-throttle valve therein, a casing extending downward into said inlet and having a fuel reservoirportion and a nozzle receiving portion, a plunger in said reservoir portion for ejecting fuel therefrom, a nozzle in said nozzle receiving portion normally holding said plunger from operation and a mechanical connection between said throttle and nozzle for lowering the latter upon the opening of the former whereby said plunger is permitted to function to eject fuel.

8. In a carburetor, the combinationwith' aa fuel reservoir and a nozzle support, a nozzle vertically adjustable within said nozzle support, a mechanical connection between said throttle and nozzle for actuating the latter from the former, and a pump plunger in said reservoir automatically actuating upon the movement of said nozzle to eject fuel therethrough. 9. A carburetor comprising a downwardly directed mixture inlet, a throttle valve controlling the same, a casing above said inlet having a cylindrical barrel portion and a portion of reduced diameter depending therefrom into said inlet, a piston in said barrel. a spring for yield.- ably pressing said piston downward. a nozzle telescopically engaging the portion of reduced diameter and forming a stop for said piston and a mechanical connection for depressing the nozzle upon the opening of the throttle. thereby withdrawing the stop and permitting the spring pressed piston to eject fuel from said nozzle. 10. A carburetor comprising a downwardly directed mixture inlet, a throttle valve controlling the same, a casing above said inlet having a cylindrical barrel portion and a portion of reduced diameter depending therefrom into said inlet, a piston in said barrel. a spring for yield-v ably pressing said piston downward, a nozzle telescopicallv en a ing the portion of reduced diameter and forming a stop for said piston, and a hollow connecting rod for drawin downward said nozzle upon the opening of the throttle, thereby withdrawing the stop and permittin the spring pre sed plunger to eiect fuel through the nozzle, said rod also constituting a fuel passage from the nozzle which registers with a port through the throttle in the idling position of the latter.

11. A carburetor comprising a downwardly directed mixture inlet, a throttle valve controlling the same, a casing above said inlet having a cylindrical barrel portion and a portion of reduced diameter depending therefrom into said inlet, a piston in said barrel,. a spring for yieldably pressing said piston downward, a nozzle telescopically engaging the portion of reduced diameter and forming a stop for said piston, a needle valve cooperating with said nozzle to form a metering idling position of the throttle registers with a port therethrough; v

12. "A carburetor comprising a throttle, a downwardly directed mixture inlet, a throttle valve therein, a casing above'said inlet having a cyli'n drical barrel portion and a depending-portion of reduced diameter extending into said inlet, a piston in the barrel portion of said casing, a spring for pressingsaid piston downward, a' nozzle slidably engaging the portion of reduced'diamfeter and forming a stop for the piston, a needle valve co-operating with said nozzle, a connectingrod between. said nozzle and said throttle for drawing downward the nozzle when thethrottle is open, and an adjustableconnectionbetween said mix; ture inlet and said casing for varying the restriction of said needle valve.

13. A carburetor comprising athrottle, a ta s-l ing forming a downwardly directed Venturi inlet passage, a throttle valve controlling said passage,

casing and overlapping the same'to form therewith a return bent air inlet, a casing centrally depending from said bell shaped casing having a barrel portion and a portion of reduced diameter extending downward into said Venturi inlet, a piston in said barrel, a tubular stem in said piston, a spring for yieldably pressing said piston downward, a nozzle slidable in said portion of reduced diameter and forming a stop for said tubular stem, a needle valve in said tubular stem cooperating with said tubular stem and nozzle to variably restrict the passage of fuel therethrough, and a hollow connecting rod for drawing downward said nozzle by the opening of said throttle forming a fuel passage from said nozzle which in the idling position of the throttle registers with a port therethrough and in the open position of the throttle is cut off from communication with said port.

14. A carburetor comprising'a casing forming a downwardly directed Venturi shaped mixture inlet, a throttle valve therein, a bell shaped casing above and overlapping said first mentioned casing to form in connection therewith a return bent air inlet, a casing depending. centrally from said bell shaped casing having a barrel portion and a portion of reduced diameter extending downward into said Venturi passage, a loose fitting plunger in said barrel, a tubular stem for said plunger, a spring for pressing said plunger downward, a needle valve in said tubular stem, a member for supporting said needle valve in said tubular stem, and an abutment for said spring,

a nozzle telescopically engaging said portion of reduced diameter forming a stop for said tubular stem and cooperating with said needle valve to variably restrict the flow of fuel, a mechanical connection for drawing down said nozzle upon the opening of said. throttle, a cup shaped on said plunger for sealing against said piston when said nozzle is depressed to positively eject the fuel through said nozzle.

15. A carburetor comprising a mixture inlet, a throttle valve controlling the same, a casing hav ing a cylindrical barrel portion containing liquid fuel and a portion of reduced diameter extending therefrom into said inlet, a piston in said barrel, a spring for yieldably pressing said piston to discharge the liquid, a nozzle telescopically engaging the portion of reduced diameter and a bell shaped casing above said first mentioned forming a stop for said piston and a mechanical connection between said nozzle and throttle for withdrawing the stop as the throttle is opened.

16. In a carburetor, the combination with a mixture inlet, of a throttle valve therein, a casing containing liquid fuel, a piston for displacing the fuel from said casing, a tubular shank for saidsaid needle valve is proportional to the displace-- ment of said piston and the latter is proportional to the opening of the throttle.

17.,"In a carburetor, the combination with a mixture inlet, a throttle valve therefor, a movable nozzle extending into said mixture inlet and mechanically connecting with said throttle, a casing having a cylindrical barrel for containing liquid'fuel and an extension for telescopically engaging said nozzle, a piston in said barrel, a

spring actingupon said piston to press the same against said nozzle, a tubular shank for said piston telescopically engaging said nozzle and forming the" discharge conduit for the liquid fuel in said barrel, and a stationary needle valve cooperating with said tubular shank to vary the discharge opening for the fuel in. proportion to displacement of the piston.

JAY S. CULP. 

